Compared with carbon, oxygen, hydrogen, nitrogen, etc., metal elements such as sodium, potassium, calcium, magnesium, iron, copper, zinc, nickel, etc., are not necessary in a large amount for living bodies. However, these are essential elements for keeping normal biological functions. Such metal elements are usually administrated with living bodies in the form of a compound comprising ionized metal elements (metal ion compounds) such as salts, and exert respective functions in the bodies.
It is known that magnesium and calcium are minerals involving enzymatic reactions in human bodies, and are required in relatively large amounts. Deficiencies of magnesium and calcium cause of bone-thinning osteoporosis and osteomalacia because these metal elements are present in relatively large amounts in the bone of living bodies. Recently, a deficiency of magnesium has been recognized as a cause of diseases such as diabetes and hypertension.
Magnesium is an essential mineral for plants, and is generally supplied to plants as a fertilizer, with a nitrogen, phosphorus, and potassium, in a liquid or solid form and used for their growth. It is known that a deficiency of magnesium causes its a deficiency disease. While various metal elements are essential to living bodies as described above, there is a case that metal ion compounds such as salts induce unpleasant tastes depending on the amount when orally administrated. Therefore, the problem of metal ion compounds in the field of food industries is recognized mainly as their unpleasant tastes when orally administrated, and various studies have been done to solve the problem.
The present inventors have widely studied mainly on the developments and uses of novel food materials with the focus on saccharides and saccharide-related substances. As a part of the study, the present inventors have studied on compositions comprising saccharides and metal ion compounds for their novel and effective uses in food industries. In the study, the present inventors found the facts that metal ion compounds, usually used in the field of foods, had unpleasant properties such as deliquescence, reducing power, oxidizing power, low solubility in water, etc., for the production and preservation of foods or their raw materials; that the unpleasant properties have been usually presumed to be inherent and unimproved properties of metal ion compounds; and that they have never been recognized as problems to be solved. The present inventors thought that the development of preparations of metal ion compounds with improved unpleasant characteristics and their supplies would greatly contribute to the food industries.
The present invention solves a quite novel object raised on the basis of original concept of the present inventors by providing preparations comprising metal ion compounds or bittern components whose inherent and inconvenient properties for industrial application such as deliquescence, reducing power, oxidizing power, low solubility in water, etc., are improved.